import {Injectable} from '@angular/core';

@Injectable()

export class verifyService {
  public textCode: string;

  constructor() {

  }

  getTextCode() {
    return this.textCode
  }

  getAllLetter() {
    let letterStr = "a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z";
    return letterStr.split(",");
  }

  //初始化验证码
  _init(option) {
    let options = option
    let con = document.getElementById(options.id);
    let canvas = document.createElement("canvas");
    options.width = con.offsetWidth > 0 ? con.offsetWidth : "100";
    options.height = con.offsetHeight > 0 ? con.offsetHeight : "30";
    canvas.id = options.canvasId;
    canvas.width = options.width;
    canvas.height = options.height;
    canvas.style.cursor = "pointer";
    canvas.innerHTML = "您的浏览器版本不支持canvas";
    con.appendChild(canvas);
    canvas.onclick = function () {
      this.refresh(this.options);
    }.bind(this)
  }

  randomNum(min, max) {
    return Math.floor(Math.random() * (max - min) + min);
  }

  randomColor(min, max) {
    var r = this.randomNum(min, max);
    var g = this.randomNum(min, max);
    var b = this.randomNum(min, max);
    return "rgb(" + r + "," + g + "," + b + ")";
  }

  canvas;
  ctx: CanvasRenderingContext2D;

  refresh(options) {
    options.code = "";
    this.canvas = <HTMLCanvasElement>document.getElementById(options.canvasId);
    // console.log(this.canvas.getContext('2d'))
    if (this.canvas.getContext) {
      var ctx = this.canvas.getContext('2d');
    } else {
      return;
    }
    ctx.textBaseline = "middle";

    ctx.fillStyle = this.randomColor(180, 240);
    ctx.fillRect(0, 0, options.width, options.height);

    if (options.type == "blend") { //判断验证码类型
      var txtArr = options.numArr.concat(options.letterArr);
    } else if (options.type == "number") {
      var txtArr = options.numArr;
    } else {
      var txtArr = options.letterArr;
    }

    for (var i = 1; i <= 4; i++) {
      var txt = txtArr[this.randomNum(0, txtArr.length)];
      options.code += txt;
      this.textCode = options.code;
      ctx.font = this.randomNum(options.height / 2, options.height) + 'px SimHei'; //随机生成字体大小
      ctx.fillStyle = this.randomColor(50, 160); //随机生成字体颜色
      ctx.shadowOffsetX = this.randomNum(-3, 3);
      ctx.shadowOffsetY = this.randomNum(-3, 3);
      ctx.shadowBlur = this.randomNum(-3, 3);
      ctx.shadowColor = "rgba(0, 0, 0, 0.3)";
      var x = options.width / 5 * i;
      var y = options.height / 2;
      var deg = this.randomNum(-30, 30);
      /**设置旋转角度和坐标原点**/
      ctx.translate(x, y);
      ctx.rotate(deg * Math.PI / 180);
      ctx.fillText(txt, 0, 0);
      /**恢复旋转角度和坐标原点**/
      ctx.rotate(-deg * Math.PI / 180);
      ctx.translate(-x, -y);
    }
    /**绘制干扰线**/
    for (var i = 0; i < 4; i++) {
      ctx.strokeStyle = this.randomColor(40, 180);
      ctx.beginPath();
      ctx.moveTo(this.randomNum(0, options.width), this.randomNum(0, options.height));
      ctx.lineTo(this.randomNum(0, options.width), this.randomNum(0, options.height));
      ctx.stroke();
    }
    /**绘制干扰点**/
    for (var i = 0; i < options.width / 4; i++) {
      ctx.fillStyle = this.randomColor(0, 255);
      ctx.beginPath();
      ctx.arc(this.randomNum(0, options.width), this.randomNum(0, options.height), 1, 0, 2 * Math.PI);
      ctx.fill();
    }
  };


  GVerify() {
    return function (option) {

      this.options = { //默认options参数值
        id: "", //容器Id
        canvasId: "verifyCanvas", //canvas的ID
        width: "100", //默认canvas宽度
        height: "30", //默认canvas高度
        type: "blend", //图形验证码默认类型blend:数字字母混合类型、number:纯数字、letter:纯字母
        code: ""
      };
      this.options = option;
      if (Object.prototype.toString.call(this.options) == "[object Object]") {//判断传入参数类型
        for (var i in this.options) { //根据传入的参数，修改默认参数值
          this.options[i] = this.options[i];
        }
      } else {
        this.options.id = this.options;
      }
      this.options.numArr = "0,1,2,3,4,5,6,7,8,9".split(",");
      this.options.letterArr = this.getAllLetter();
      this._init(this.options);
      this.refresh(this.options);
      return this.options.code;
    }.bind(this)

  }
}
